A monitor camera is installed at a monitoring place for shooting an object to be monitored. The place to install the monitor camera may be an outdoor. FIG. 8 is a perspective view of an example of the monitor camera in the related art. A monitor camera 30 includes a camera case 31 and a front glass 32. The front glass 32 is formed of a transparent glass plate and, in an example shown in the drawing, has a square shape. The camera case 31 has a substantially square tubular shape in cross section, and includes an imaging device including a lens, an imaging element, and a processing circuit stored therein. The monitor camera 30 picks up an image of an object of shooting, which is an object to be monitored through the front glass 32 and shoots the object of shooting.
The camera case 31 holds a periphery of the front glass 32. An end of the camera case 31 is bent inwardly to form a front wall and the front glass 32 is held from the side of an outer surface thereof at an opening of the front wall.
FIG. 9 is an enlarged cross-sectional view showing a holding position at which the camera case 31 holds the front glass 32. The front glass 32 is pressed from a rear side thereof by a glass holding plate 33 against an inner surface of the front wall of the camera case 31 and fixed thereto. The glass holding plate 33 is fixed to the camera case 31 with screws. An O-ring 34 is provided at a portion where the front glass 32 and the camera case 31 come into abutment so that the waterproof property of the camera case 31 is secured.
As described above, in the monitor camera 30, the camera case 31 presses the front glass 32 from the side of the outer surface to hold the front glass 32. Accordingly, as shown in FIG. 8 and FIG. 9, the outer surface of the front glass 32 is stepped back inwardly in comparison with an outer surface of the camera case 31, and hence a step is formed. When the monitor camera 30 is installed in outdoor, natural substances such as snow or dust may be accumulated on the step. When snow is accumulated on the step, a field of view through the front glass 32 of the monitor camera 30 is hindered, and hence part of the image of the object to be monitored cannot be obtained.
In view of such points, for example, a camera case having a configuration as shown below is disclosed in JP-A-2002-156702 (pp. 2-3, FIG. 3). FIG. 10 shows a front view of the camera case. A front glass 42 is fitted to a front panel 43 of a camera case 41. A defroster glass 44 for removing water drops or fogging up is provided in front of the front glass 42. The defroster glass 44 is pressed against the front glass 42 from the side by a glass presser 45. Then, an annular packing groove 46 is provided at a part where the front panel 43 supports the front glass 42, and a packing 47 is fitted to the packing groove 46. The defroster glass 44 comes into tight contact with the packing 47 by being pressed by the glass presser 45. Accordingly, the waterproof property in the camera case 41 is secured.
As shown in FIG. 10, the defroster glass 44 has a tapered shape having an inclined portion 441 inclined so as to increase the diameter toward a surface of the front glass 42. The glass presser 45 has a tapered shape provided with an inclined portion 451 corresponding to the inclination of the inclined portion 441 of the defroster glass 44. The height of a surface of the glass presser 45 is set to be the same as or the lower than the height of the defroster glass 44 in a state in which the inclined portion 441 of the defroster glass 44 is held down by the inclined portion 451 of the glass presser 45. In this arrangement, the step caused by the glass presser 45 being higher than the defroster glass 44 is eliminated from the camera case 41, so that the field of view of the monitor camera is prevented from being hindered by snow accumulated on an outer surface of the defroster glass 44.
However, with the camera case 41, the inclined portion 441 of the defroster glass 44 is pressed by the inclined portion 451 of the glass presser 45, so that the defroster glass 44 is fixed. Therefore, when a tolerance of the defroster glass 44 is large and the dimensional accuracy is low, there is a case in which the defroster glass 44 does not come into tight contact with the packing 47 sufficiently in a state in which the glass presser 45 is fixed to the camera case 41. In this case, the waterproof property of the camera case 41 is lowered.